Electric signaling or controlling system



w n VA- Y. u. A* w A A "UWM n u v M Y uw Y 4 Y Y, m .Y V Y A -f/ Nov. 1, 1938. R. J. WEY 5:3 f *2,134,901 ELECTRIC SIGNALNG. OR CONTROLLING SYSTEM A' Fil'ed July 2, 193s s sheets-sheet 1 D@ il p 1Jl Y gf Mofor v y Mews/Bava,

Nov. 1, 1938. R, 1 WEY 2,134,901

ELECTRIC SIGNAL-ING OR GONTROLLING-SYSTEM 'Filed July 2, 1956 s sheets-sheet 2 Fig. S. Fig 4.

g A v.Fi-g5@ /NVE/V' RHYMa/VD JoHN WEY Nov. L 1938.

R. J. WEY

ELECTRIC SIGNALING OR CONTROLLING' SYSTEMl Filed July 2, l1935 l 3 Shets-Sheet- 3 Patented Nov. 1, 1938 Raymond John Wey,

Park Royal, London, England, assignor to -Republic Flow Meters Company, Chicago, Ill., a corporation of Illinois Application July Z, 1.936,- Serial No. 88,543 In Great Britain July 8, 1935 10 Claims.

.'I'his invention relates to regulating. remotecontrol, repeating, recording, compensating, in-

dicating or controlling systems and has particular reference to systems employing follow-up or other devices in which the position or condition of one element in one circuit is varied whenever the position or condition of another element included in an associated circuit is varied, for follow-up,

. balance-restoring or like purposes. Such devices are frequently used in various forms of indicating, recording, integrating, regulating, repeating, compensating or control units and the chief object of the present invention is to provide animproved form of signaling or controlling system possessing a high degree of sensitivity.

According to one feature of the invention the system is equipped with a follow-up, balance-restoring or like device comprising a magnetic core or transformer carrying one or more windings through which the current in a primary or controlling circuit and that in a secondary or followup circuit are passed and mutually combined by addition or subtraction to produce a resultant voltage drop across such windings and to induce in one or more otherwindngs a voltage proportional to the said voltage drop, the arrangement being such that when the voltage drop departs from a predetermined value or the circuits become mutually unbalanced a relay device associated with the Secondary or follow-up circuit is actuated to restore the circuits to their balanced condition. A

According to another feature of the invention the voltage induced in said windings is applied to grid element or elements of one or more'thermionic valves or gas lled relays and the resultant variation in the anode current is utilized to cause through the intermediary of an electric motor or other convenient source of motive power, a variation in an electrical characteristic of the secondary or follow-up circuit of such a nature that the voltage drop tends to return to its normal or predetermined value.

According to a further feature of the invention the magnetic core or transformer is provided with means for controlling the impedance offered by the winding or windings traversed by the priv mary or secondary currents, thereby enabling the sensitivity of the device to be accurately controlled. Said means may comprise means for enabling the reluctance offered by the core to be varied, e. g. by variations in an air gap in the magnetic circuit, or they may comprise a variable external impedance associated with a special or additional winding on the core or with one of the (ci 17a-239) existing windings thereon. Said external empedance may take the form of a resistance or reactance or a combination of both, e. g. a condenser or inductance used in conjunction with a resistance or separately. If desired, the external impedance may have a xed value and the number of turns of the transformer winding to whichv the impedance is connected may be made variableby means of tappings, it being appreciated that the greater the number-of turns included-in circuit, the greater will be the effect ofthe external impedance in modifying the impedance of -the balancing transformer. In order to reduce errors due to stray magnetic iiux between the various windings, as distinct from the flux passing through the core, the vari'- ous windings may be interlaced or subdivided so as to reduce the possible path for stray flux to a minimum. Also, if desired. the transformer may be provided with a metallic screen or screens between the windings or sections thereof so as to reduce the effect of stray magnetic iiuxes between the windings and to eliminate electrostatic interaction. Also, for the forming of the core of the transformer use may be made of a high permeability alloy in the form of laminations so as to r`ev duce the number of turns and physical dimensions necessary to obtain a given impedance.

It will be appreciated that the effective value of the external impedance may be varied by hand to suit the particular use for which the device is to be employed or, if desired, the impedance varying means may be coupled with a' variable or displaceable element of the secondary or follow-up circuit to permit the sensitivity of the device to be varied 35 automatically to suit different operating conditions.

Where the induced voltage is applied tothe grid element or elements of one or more thermionic valves or gas filled relays, the grid coil or coils 40 may be wound on the same spool as the primary or secondary coils, or 'in association with them, and may, if desired, be subdivided, but it is preferred to separate the grid coils into two separate and distinct windings arranged over the other windings, or one at each end, so that the effect of stray uxes from the primary or secondary windings on the two .grid windings may be made equal and negligible.

In order to prevent excessive magnetization resulting in a temporary or a. permanent alteration. of the magnetic properties of the c ore, a non-linear impedace, e. g. a rectiiier, is preferably connected acoss one of the windings, the characteristic of the impedance being such that its effective impedance value will fall rapidly with increasing applied voltage. In this manner, the voltage drop across such winding can be kept below a predetermined value and the voltage drops across the other windings can be prevented from exceeding proportionate values. Such non-linear impedance may be connected with any of the aforesaid windings or it may be connected with a special or additional winding. Usually, however, it is preferable to connect the non-linear impedance to the same winding as the external linear impedance, such winding being provided with tappings to enable 'the relative voltages across the two impedances; to be adjusted.

The aforesaid primary elementmay form part j of a measuring instrument or it may be constituted by an element the condition or position of which is caused to vary with a physical, electrlcal or other characteristic such as, for example, velocity, fluid ow, temperature, or pressure.

In order that the said invention may be clearly understood and readily can-ied into effect, the same will now be more fully described with reference to the accompanying drawings, in whichzif Fig. 1 illustrates diagrmmatically one convenient mode of carrying the invention into effect;

. Fig. 2 illustrates a modication employing relays of the thermionic type;

Figs. 3 to' '7 illustrate alternative modes of changing the value of the inductance of the balancing transformer and of protecting the transformer fromthe effects of strayzux; and Fig. 8 illustrates diagrammatically another mode of carrying the invention into effect.

In the embodiment of the invention shown in Fig. 1, the primary circuit comprises a winding.

A on a core E and in series with a controlling resistance R and a supply transformer winding I. The effectiv e value of the resistance R is The core E also carries an additional'winding f e any departure from a predetermined voltage induced in the winding f will cause the motor H to rotate in one direction orithe other. That is to sayfwhen the currents in the primary andv secondary windings A and B are such as to produce the normal or predetermined voltage on the winding f, the arrangement is in equilibrium and no rotation of the motor takes place, but ii' the resistance R varies causing the current in winding A to vary, the voltage induced in J' will depart from its normal value and the motor H will displace the contact arm of the variable resistance D, thereby altering the current in B until the balance is once more restored.

'I'he aforesaid relay may be of any known type e. g. electro-mechanical, or it may be of the thermioriic type such as is comprised by the two gas-filled relays G1 and G: shown in Fig. 2. In this embodiment, the grids of the relays are connected respectively to the grid windings C and D on a balancing transformer T and the anodes of the relays are each connected through the. eld windings of the reversible electric motor H to a source of anode current supply derived from' 5 a transformer Ji which also supplies grid Vbias'` from a tapping on its secondary winding. The' primary or controlling element or elements com- Yprises one or more resistances or impedances F and F1 the effective values of`wl1'ch` are caused 1 to vary in 'liw'im'nwitlivariations in the physical quantity being controlled, recorded or compensated, and the current in the primary circuit or circuits passes through the windings A and B on -the transformer T. l

Thesecondary current passes' through a variable resistance K and a third winding L on the transformer T and the resultant magnetization of the core will thus depend upon the sum of the amp! t11rns due to A, B and L. T'eiiagnetization of the core results in a voltage being induced in the windings C and D, which voltage is applied to the grids of the gas-filled relays G1 and G2 so that according to the polarity .of this voltage with respectme-Wltage. eitler ong 25 or'theother of these relays will be caused to pass series with the inductance v. The accuracy of fj anode current. The motor is thus caused`t`- tate in one direction or the other and by virtue of the motor beiingpgpledftodhe resistance K the latter -is var ed so that the cm in the 30 secondary cmpamtfgggthe "winding L is adjustedlntil magnetization of the core is brought back to its normal value, which may be zero imoiound expedient.

It win be appreciated that the variable 'resist- 35 ance and the motor H are, as in the previously described embodiment together coupled to the compensating, controlling or recording mechanism. 'Ihe supply of current for the primary and secondary circuits may be derived from the 4 same source as the anode and grid bias supply for the gas-filled relays and the two circuits may be fed from a common winding or separate Windings of suitable transformers as shown.

As mentioned above, in some instances, -it is necessary or advisable to alter the value 'of inductance of the balancing transformer in order to provide a control over the voltage developed in these windings for a certain out-of-balance of the two currents in the primary and secondary windings. One method of effecting-such altera-L tions is to vary the reluctance of the core of the transformer by means of a variable air-gap in' known manner, but another method which may .be more convenient is inductively to couple withthe balancing transformer an external impedance and to vary the value of this external impedance. For example, as is illustratedin Fig. 3, the primary and secondary windings A and B on a core E are inductively coupled by means of a winding P to the impedance Z, which impedance may be a simple resistance, inductance or impedance, or it may be a composite impedance of resistance u i and inductance v, as shown for example in Fig.4, A and in order to vary the value of the impedance, G either the resistance or the inductance, or both, may be m'ade variable and/or the winding P may be tapped as shown. In the alternative method of connection shown in Fig. 4, the resistance u is in the transformer of this nature may be affected by stray or leakage eldsdue to the passage of mag; netic flux through the space surrounding thej windings as distinct from the ux passing through,

the core of the transformer. This effect may bef'ls eliminated or minimized by providing metallic shields over one or more of the windings in such a manner that the stray flux is prevented from affecting the adjacent windings and that the only common ux linking the various windings is that passing through the core 'of the transformer.

For example, as is illustrated in Fig. 5, the windings A and B constituting the primary and secondary windings may be wound on a core E and the windings C and D constituting the grid .windings may be Wound over the primary and secondary windings in such a manner that metallic shields g, h and i are interposed between the windings and around the outsidesin the mannershown, thus screening the stray flux so that no voltages are induced in the windings C and D, except by the flux in the core E.

Another -method by which the eifect of stray ux can be reduced is to interlace or sub-divide the windings so that they are physically as close as possible to one another and furthermore to arrange them symmetrically so that the eifects of stray fields tend to cancel out. Such an arrangement is indicated in Fig. 6 in which the primary winding A and the secondary winding B are subdivided in a number of sections alternately arranged in the manner shown, the grid windings C and D being placed at either end of the primary and secondary windings. 'Ihe auxiliary winding to which the external impedance is connected for the purpose of modifying the impedance of the transformer itself, may be wound in -secticns aiso interleaved with the primary and secondary windings. An alternative method is :hown in Fig. 'i' in which the two grid windings C and D are arranged outside the interleaved primary and secondary windings A and B.

Since it may necessary to vary the sensitivity ofthe device according to varying physical conditions, vit is possible to vary mechanically the external impedance according to the movement of the follow-up or balancing resistance.

Referring to Fig. 8, it will be seen that the aux'.

iliary winding L is connected to a variable impedance Z which is coupled mechanically to the driving-motor H and the balancing resistance K in the manner shown. Thus the sensitivity of the transformer can be varied according to the value 'of the balancing resistance K which, in turn, is

dependent upon the current i'iowing in the primary circuit A, since this controls the current in the secondary circuit B. Other means of performing this adjustment automatically according to the movement of the follow-11p or balancing member may used without departing from the scope of thennvention, e. g. the air-gap in the core may be varied instead .of the' external impedance.

In order to prevent excessive magnetization of the core resulting'from momentary out-of-balance of the two currents in the primary and secondary windings, due, for instance, to time delay in the operation of the follow-up motor H, the

core may become highly magnetized, which would result in the accuracy being affected. 'I'his excessivev magnetization may be prevented by the connection of a voltage-limiting device across one winding of the transformer, for instance across the auxiliary winding to which the external impedance is connected. -This voltage-limiting device may take the form of a rectifier S which has the characteristic of rapidly decreasing resistance with increasing applied voltage. Thus, owing to the limited value of the current which may now in the auxiliary winding due to maximum out-oibalance of the primary and secondary currents, the voltage across the rectifier will never grid or relay'windings of the balancing trans-V former; the core of this may be constructed of high permeability alloy.

Having thus described this invention'what I claim as new therein and desire to secure' by Letters Patent is:

1. A telemetric system comprising means for producing electric currents varying in accordance with variations in one or more quantities or factors, means for producing an electric current varying in accordance with the condition of a controlled member, 'a transformer having windings adapted mutually to combine the said currents in such a manner that any departure from the normal value of current in any winding is adapted to cause the operationy of arelay connected to a winding of the transformer, said relay controlling the supply of current to a reversible electric motor coupled with the controlled member.

2. A system of the character described comprising means for producing an electric current varying with variations in one factor, means for producing another electric.' current varyingcwith the condition of a controlled member, a transfermier having windings mutually combining said .having windings disposed mutually to combine said currents, a relay operated by departure from the normal current value of the current in any winding. of the transformer, said relay including a 'thermionic valve with the control grid thereof connected to a grid winding of the transformer, and a reversible electric motor controlled by the relay and connected in the anode circuit of the thermionic valve and connected to the controlled member to operate it.

4. A system of the character described comprising means producing an electric current vary- .ing with variations in one factor, means producing another electric'current varying with the position of a controlled member, a transformer hav-- ing windings disposed mutually to combine said currents, said transformer having an auxiliary winding connected withan external variable impedance, a relay operated by departure from the normal current value of. the current in any winding of the transformer, andan electro-mechanical device coupled with the controlled member, the supply of current to the electro-mechanical device being controlled by the relay. y

. 5. A system of the character described comprising means producing a primary electric current varying with variations in one factor, means producing a secondary electric current varying with the position of a controlled member, a transformer having windings disposed mutually to combine said primary and secondary currents and to produce a resultant voltage drop across said windings, means controlling the impedance offered by the winding or windings traversed by the primary and secondary currents, a relay operated by departure from the normal current value of the current in any winding of the transformer and an electro-mechanical device coupled with the controlled member and controlled by 'by departure from the 4normal current value of the current in any winding of the transformer, and an electro-mechanical device coupled with the controlled member, the supply of current to the electro-mechanical device being controlled by the relay.

7. A system of the character described comprising means producing an electric current varying with variations in one factor, means producing another electric current .varying with the position of a controlled member, a transformer having windings disposed mutually to combine said currents, said transformer having an auxiliary winding connected with an external impedance, means varying the value of the external impedance in accordance with the position 'of the controlled member, a relay operated by departure from the normal current value of the current in any winding of the transformer, and an electro-mechanical device coupled with the controlled member, the supply of current to the electro-mechanical device being controlled by the n relay.

ing another electric current varying with the4 position of a controlled member, a transformer having windings disposed mutually to combine said currents, said transformer having a core provided with an fair gap, means varying said air gap in accordance with the position oi' the controlled member, a relay operated by departure from the normal current value of the current in any winding of the transformer, and an electromechanical device coupled with the controlled member, the supply of current to the electro-mechanical device being controlled by the relay.

9. A system of the character described comprising means producing an electric current varying with variations in one factor, means producing another electric current varying with the position of a controlled member, a transformer having windings disposed mutually to combine said currents, a relay operated by departure from the normal current value of the current in any winding in the transformer, said relay including two 'thermionic valves having their control grids connected to windings on the transformer, and a reversible electric motor having its windings connected in the anode circuits of said thermionic valves and connected to the controlled member to operate it.

10. A system of the character described comprlsng means producing an electric current varying with variations in one factor, means produc-` ing another eiectriccurrent varying with the `pcsition of a controlled member, a transformer 

